Cefamandole failure in ampicillin-resistant Haemophilus influenzae b pneumonia.

A woman with rheumatoid arthritis and ampicillin-resistant Haemophilus influenzae type b (Hib) pneumonia complicated by bacteremia and empyema is reported. Initial therapy with cefamandole failed to eliminate bacteria from the pleural space and did not substantially affect the clinical course. However, cultures became negative and fever resolved when therapy was changed to chloramphenicol. Ampicillin-resistant Hib pneumonia in adults is an increasing problem and may be a difficult diagnosis to establish initially. Counterimmunoelectrophoresis may be useful in adults with pneumonia. If Hib antigen is detected, or if H influenzae is suspected on the basis of Gram stains and cultures, chloramphenicol should be given until the isolate is shown to be sensitive to ampicillin.